AU706306B2

AU706306B2 - Method for reprocessing medical devices utilizing a room temperature sterilant

Info

Publication number: AU706306B2
Application number: AU74463/96A
Authority: AU
Inventors: Robert T. Ii Hall; Bradley K Onstad
Original assignee: Minntech Corp
Current assignee: Minntech Corp
Priority date: 1995-11-17
Filing date: 1996-10-11
Publication date: 1999-06-10
Anticipated expiration: 2016-10-11
Also published as: CA2235401C; EP0881876A4; AU7446396A; JPH11500049A; US5589507A; CA2235401A1; EP0881876A1; WO1997018707A1

Description

WO 97/18707 PCT/UJS96/16573 METHOD FOR REPROCESSING MEDICAL DEVICES UTILIZING A ROOM TEMPERATURE STERILANT BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a room temperature anti-microbial composition which includes an ester of formic acid, an oxidizer, performic acid, and water, a premix for making the anti-microbial composition, and a method for producing the anti-microbial composition.

2. Background of Related Art Conventional methods of sterilizing medical devices have significant disadvantages. For example, the steam autoclave works well, but many instruments are sensitive to the high pressure and temperature required to achieve sterility. Ethylene oxide requires long exposure times in a vacuum, even longer aeration times, and the gas is highly toxic.

Glutaraldehyde is a suspected carcinogen and can be corrosive to certain materials.

SUMMARY OF THE INVENTION An object of the present invention is to provide an easy to use room temperature anti-microbial composition.

A further object of the present invention is to provide an anti-microbial composition for sterilizing medical devices which overcomes the disadvantages of known methods of sterilizing medical devices.

The invention relates to an anti-microbial composition having improved anti-corrosive properties comprising an ester of formic acid, an oxidizer, performic acid and water.

A preferred embodiment of the invention relates to an anti-microbial composition having improved anti-corrosive properties comprising about .01 to 10 wt.% of an ester of formic acid selected from the group consisting of ethyl formate, methyl formate, propyl formate, or mixtures thereof, about .01 to 10 wt.% of an oxidizer, about .001 to 5 wt.% of performic acid, and up to about 99.98% water.

The invention also relates to a premix for making the anti-microbial composition comprising two parts. One part comprises the ester of formic acid and a second part comprises the oxidizer.

The invention further relates to a method making the anti-microbial composition comprising the steps of combining the premix.

The invention also relates to a method of producing the anti-microbial composition comprising the steps of combining an ester of formic acid with an oxidizer and water.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1. illustrates the sporicidal effects of the anti-microbial composition according to the invention compared to two conventional anti-microbial compositions.

Fig. 2. illustrates the bactericidal effects of the anti-microbial composition according to the invention compared to two conventional 30 anti-microbial compositions.

Fig. 3. illustrates the net mass loss of brass after 24 hours of exposure as measured in Example 2.

Fig. 4. illustrates the concentration of performic acid in hard and deionized water over time as measured in Example 3.

Fig. 5. illustrates the concentration of hydrogen peroxide in hard and deionized water over time as measured in Example 3.

Fig. 6. illustrates the stability of hydrogen peroxide and performic acid in deionized water over time as measured in Example 3.

DETAILED DESCRIPTION. OF THE PREFERRED EMBODIMENTS *e The invention relates to an anti-microbial composition having improved anti-corrosive properties comprising an ester of formic acid, an oxidizer, performic acid and water.

Preferably, the anti-microbial composition comprises about .01 to 10 wt.% of the ester of formic acid, about .01 to 10 wt.% of an oxidizer, about .001 to 5 wt.% of performic acid, and up to about 99.98 wt.% water. More preferably, the anti-microbial composition comprises about 2 to 8 wt.% of the ester of formic acid, about 1 to 10 wt.% of an oxidizer, about .001 to 1 wt.% of performic acid, and up to about 97 wt.% of water.

Preferably, the ester of formic acid is an 0 ester of ethyl formate, methyl formate, propyl formate, or mixtures thereof. More preferably, the ester of formic acid is ethyl formate.

The oxidizer can be any oxidizer that is compatible with a performic acid based anti-microbial composition. Examples of such oxidizers include nonorganic oxidizing substances such as, hydrogen peroxide, sodium percarbonate, sodium periodate, sodium persulfate, ammonium persulfate, sodium perborate, sodium peroxide, calcium peroxide, silver (II) oxide, ozone, and chlorine dioxide. The oxidizers also include organic oxidizing substances, for example, diacyl peroxides, such as benzoyl peroxide, ketone peroxides, such as 2, 4-pentanedione peroxide, peroxydicarbonates, such as diisopropyl peroxydicarbonate, peroxyesters, such as t-butylperoxy maleic acid, dialkyl peroxides, such as dicumyl peroxide, hydroperoxides, such as t-butyl hydroperoxide, and peroxyketals, such as 2,2-di(tbutyl peroxy) butane.

Preferably, the oxidizer is hydrogen .*15 peroxide. More preferably, the oxidizer is urea hydrogen peroxide.

A preferred anti-microbial composition comprises ethyl formate in an amount of about 3.8 to 4 urea hydrogen peroxide in an amount of .20 about 1 to 8 and about .001 to 1 wt.% of performic acid.

The anti-microbial composition can also contain additives, such as, corrosion inhibitors and stabilizers.

Examples of corrosion inhibitors are 1,2,3- Benzotriazole, azimidobenzene and benzene azimide S' (collectively, COBRATEC 99T, PMC Specialties Group, Inc.) and the sodium hydroxide reaction products of an aliphatic alcohol and phosphorous pentoxide (VICTAWETM 35B, Akzo Chemicals, Inc., Chicago, IL).

The corrosion inhibiting properties of VICTAWETr are disclosed in PCT/US90/01862, entitled "Anticorrosive Microbicide." The stabilizers include those that stabilize the anti-microbial composition over time, and those that increase the concentration of performic acid, as well as other stabilizers.

The anti-microbial composition can be made in a concentrated form, dry or liquid, to be diluted with water before using.

Purifying the water is not required. When hard tap water is used, surprisingly, the concentration of performic acid in the anti-microbial composition is less likely to decrease or will increase at the expense of the oxidizer, compared to deionized water. This is a significant advantage, because tap water is more readily available and is less expensive than purified or deionized water. In particular, hard water containing calcium acts in this 15 manner.

The invention also relates to a premix for making the anti-microbial composition comprising a first part comprising an ester of formic acid, and a second part comprising the oxidizer. The oxidizer and ester of formic acid include those described above.

The anti-microbial composition can be formed by combining the first and second parts with water.

Preferably, the first part comprises an ester of ethyl formate, methyl formate, propyl formate, or mixtures thereof, and the second part comprises hydrogen peroxide.

Preferably, the amount of the ester of formic acid in the first part and the amount of oxidizer are such that when combined with water the 0 resulting anti-microbial composition comprises about .01 to 10 wt.% of the ester of formic acid, about .01 to 10 wt.% of the oxidizer, about .001 to 5 wt.% of performic acid, and up to about 99.98% water.

Each part of the premix can be in a dry or licruid form. For example, one or both parts of the

I

CO CO

C

*0 S. C .me 4 .me.

0.06

C

0O4 premix can be diluted with water. Alternatively, one part can contain all of the required water so that when the other part is added no further water is required, or sufficient water is present in both parts so that when both parts are combined no further water is required.

The premix can also contain the above described additives in either or both of the parts.

The invention further relates to a method of making the anti-microbial composition comprising the steps of combining both parts of the pre-mix. If the pre-mix does not contain the required amount of water, water and the first and second parts can be mixed in any order.

15 Another embodiment of the invention relates to a method of producing the anti-microbial composition comprising the steps of combining the ester of formic acid with the oxidizer and water.

Preferably, sufficient amounts of water, .20 ester of formic acid, and oxidizer are combined so that the resulting anti-microbial composition comprises about .01 to 10 wt.% of the ester of formic acid, about .01 to 10 wt.% of the oxidizer, about .001 to 5 wt.% of performic acid, and up to about 99.98 wt.% water.

The anti-microbial composition can be used in place of conventional microbicides. The following is a partial list of uses for the anti-microbial composition. The uses of the anti-microbial 30 composition is in no way intended to be limited to this list.

00CC 0 0009 @4 0 0

C.

.050 S The anti-microbial composition can be used on skin, medical devices, and eating utensils.

The anti-microbial composition is particular useful for reprocessing used catheters which are sensitive to conventional anti-microbial WO 97/18707 PCT/US96/16573 compositions. Preferably, when the anti-microbial composition is used to reprocess used catheters, the anti-microbial composition contains VICTAWET 35B. It is believed that the VICTAWET acts as a lubricant for the mechanical pump during reprocessing. The reprocessing method disclosed in U.S. Patent Nos.

4,721,123 and 5,310,524 are incorporated herein.

The invention will be further described by the following non-limiting examples.

EXAMPLE 1 Three tests were performed on samples of an anti-microbial composition according to the invention (hereinafter "Performx") made by combining 3.8 to 4% by weight of ethyl formate, 4% urea hydrogen peroxide, and the balance water. Performic acid was generated in an amount of about .001 to about .1 wt.%.

The anti-microbial composition was compared to two known microbicides, CIDEX 7 (Johnson and Johnson, Medical) and 1% RENALIN II (Minntech Corporation, published in PCT/US92/05877).

In the first test, the sporicidal and bactericidal activity of each anti-microbial composition was tested by placing 1x10 10 Bacillus subtilis spores into 10 ml of anti-microbial composition in a closed, but not sealed, test tube at room temperature (about 20°C). At exposure times of 5, 7.5, 10, 12.5, 15, 17.5 and 20 minutes, 1 ml was removed and placed in a neutralizer solution to stop the sterilant action. The neutralizer solution comprised 1% Bacto-peptone (Difco), 1% sodium thiosulfate, and .025% catalase. The surviving spores were then serially diluted and plated to count.

Figure 1 illustrates the rate of kill by plotting the log number of surviving organisms vs.

exposure time. Fig. 1 illustrates that the Perform x WO 97/18707 PCT/US96/16573 curve closely fits the 1% RENALIN II curve.

Therefore, Performx exhibits anti-microbial effects equal to or greater than 1% RENALIN II. Fig. 1 also illustrates that Performx exhibits significantly greater anti-microbial effects than CIDEX 7, on the order of four logs, after 20 minutes.

The above test was repeated, except using methyl formate, butyl formate, or propyl formate in place of ethyl formate in the same molar concentration. After 20 minutes, 5 x 104 bacteria were observed and after 60 minutes no bacterial were observed in the methyl formate solution. After minutes, no bacterial were observed and after minutes 6 x 104 bacterial were observed in the propyl formate solution. The propyl formate solution was retested and no bacteria was observed after 20 and minutes. Therefore, the bacteria observed after minutes in the propyl formate solution was a procedural error. After 20 minutes, 4.3 x 107 bacterial were observed and after 60 minutes 3.3 x 106 bacteria were observed in the butyl formate solution.

A second text was performed by coating a petri dish (Falcon Corp.), containing an agar made using tryptic soy (Difco Labs), with either Staphvlococcus aureus, Pseudomonas aerucrinosa, or E.coli. After the plates were dry, three wells were punched into the agar and filled to the top with either Performx, RENALIN II or CIDEX 7. The plates were then incubated for 48 hours at 37°C. The area around the well where no bacterial grew (zone of inhibition) was then measured and graphed. Figure 2 illustrates the results. The zones where no bacterial grew were significantly larger for the Perform, than they were for RENALIN II and CIDEX 7. This data illustrates that Performx kills significantly more WO 97/18707 PCT/US96/16573 organisms than either of RENALIN II or CIDEX 7, and that Performx kills Pseudomonas spp. This is of considerable importance because CIDEX 7 has been reported to have difficulty in killing Pseudomonas spD. This test is similar to the test used for determining the relative effectiveness and/or resistance of microorganisms to antibiotics.

A third test was performed in which an AOAC 966.04 (1990) sporicidal test done on Clostridium sporogenes using suture loops as the carrier. The results are summarized in Table 1. All tests were run for 5 1/2 hours at 20°C. unless stated otherwise.

TABLE 1 Description: Results (negatives/#samples): Performx 49/50 1/2 concentration Perform, 19/20 Performx pH 7 20/20 Performx in synthetic hard water 20/20 Performx in tap water 20/20 Performx at 3 1/2 hours exposure 37/40 Performx 2 1/2 hours exposure 20/20 Performx (double)l 12 min. exp. 19/20 Performx (double)l 20 min. exp. 20/20 Performx (double)2 12 min. exp. 17/20 Performx (double)2 20 min. exp. 20/20 Performx (double)2 30 min. exp. 2.0/20 A tube is considered negative if no growth is observed after 21 days of incubating, heat shocking at for 20 minutes and then incubating again for another 72 hours.

WO 97/18707 PCT/US96/16573 1 Double the amount of urea hydrogen peroxide and ethyl formate, 2 wt.% COBRATEC 99, 2 Double the amount of urea hydrogen peroxide and ethyl formate, A difference of <5 is not statistically significant.

EXAMPLE 2 The corrosive effects of Perform, were tested using the same formulation of Performx as used in Example 1, except where noted.

In the first test, the corrosive effects of Performx and 1% RENALIN II on chrome plated Kerr dental mirrors. The Performx formulation tested was the same as in Example 1 except that it did not include COBRATEC 99 and was adjusted to a pH 7 using .1 N NaOH. The pH of Perform, before adjusting was 3.8. The mirrors were soaked at room temperature (about 20'C) in a closed container (screw on lid) for a two week period in about 120 ml of Performx or 1% RENALIN II. The solutions were changed daily by pouring out the used liquid and refilling with fresh.

This test was an appearance type of inspection process rather than a quantitative evaluation. Upon examination after the two week period, the mirrors soaked in Performx had a significantly better appearance than the mirrors soaked in 1% RENALIN II.

RENALIN II etched away the chrome layer, exposing the brass underneath. The brass was beginning to corrode which turned the 1% RENALIN II solution blue. The Performx only slightly dulled the appearance of the chrome plating.

In the second test, the corrosion effects of Performx and 3% RENALIN II on a naval brass coupons WO 97/18707 PCT/US96/16573 (approximately 12.3 gms) were tested. The Perform, tested was the same as in Example 1 except where noted.

Before testing, the brass coupons were cleaned to remove oils, dirt, etc., by placing the coupons in a glass tray containing acetone and sonicating for about 5 minutes, removing the coupons with forceps, rinsing with deionized water, and then air drying.

The coupons were then weighed (Wtl).

The method used to test the corrosion effects is outlined in the ASTM G1-90, (1992) Vol. 3.02, pp. 38. Each naval brass coupon was soaked in about 120 ml of test solution for a time period of 24 hours in a plastic specimen cup.

The rate of corrosion was measured using the mass lost during the 24 hour soak period as follows.

The naval brass coupons were removed from the test liquids, rinsed thoroughly with deionized water, dried and weighed (Wt2). The corrosion products were then removed from the tested coupons. All of the tested coupons and one blank coupon were submerged in sulfuric acid for 2 minutes while sonicating. The coupons were then rinsed thoroughly with deionized water, air dried and weighed (Wt3). Each coupon was placed on the back of a modified test tube rack in between two glass slides on each side of the coupon.

A weighted SCOTCH BRITE pad (3M Corp.) was wrapped around each coupon and the coupon was rubbed 10 times each way with the pad, allowing the weight of the pad to be the only downward force exerted on the coupons.

Both sides of the coupons were rubbed with the pad.

All of the coupons were then placed in 10% sulfuric acid and sonicated for 2 minutes. The coupons were then rinsed, air dried and weighed (Wt4). The coupons were immersed in sulfuric acid and rubbed with the pad as described above until the weight loss of the tested WO 97/18707 PCT/US96/16573 coupons was almost equal to the amount lost by the blank coupon. The weight loss of the tested coupons will not be equal to the amount lost by the blank coupon, but they will usually be within about .001 g of each other. Each weight was measured after air drying as (Wtn).

The corrosion rate was calculated using the following formula: corrosion rate (mm/yr)=(K x x T x D) where: A area of coupon in cm 2 to nearest .1 cm 2 (std 28.7 cm 2 K a constant (8.76 x 104) T time of exposure in hours to the nearest .25 hours.

W the mass lost in g, to the nearest 1mg corrected for the mass lost during cleaning (initial weight Wtn of treated coupon) minus (Initial weight Wtn of blank coupon).

D density in g/cm 3 of material tested (naval brass c-464 8.41 g/cm 3 The results are shown in Table 2 and Figure 3.

WO 97/18707 PCT/US96/16573 TABLE 2 SUBSTANCE TESTED: Performx Ph 7, 2x concentrate Performx pH 7 Performx pH 7, COBRATEC 99 Performx COBRATEC 99 Performx w/.17% COBRATEC 99 Performx VICTAWET 35B Performx VICTAWET 58 Performx pH 7, sodium nitrite Performx pH 7.8, sodium nitrite Cathx 3% RENALIN II CORROSION RATE: .57 mm/yr 1.40 mm/yr .061 mm/yr .094 mm/yr .035 mm/yr .77 mm/yr .34 mm/yr 1.26 mm/yr 1.24 mm/yr 1.10 mm/yr 4.13 mm/yr The addition of small amounts of COBRATEC 99 significantly reduced the corrosion rate of brass.

In the third test, the corrosion effects of Performx and 1% RENALIN on dental burrs and carbon steel scalpel blades was tested. The Performx and 1% RENALIN II, and the test procedures, were the same as used in the first test of Example 2, except where noted. Performx made the burrs tarnish in 24 hours, but the addition of the COBRATEC 99 almost eliminated this problem. To compare, 1% RENALIN etched the burr away. The scalpel blades showed no signs of corrosion from Performx, with or without COBRATEC. 1% RENALIN performed equally well as Performx However, deionized water (deionized using a mixed bed deionizing system) rusted the blades.

WO 97/18707 PCT/US96/16573 EXAMPLE 3 The stability of Performx was tested.

Formulas 599-81-18 through 599-81-20 used a 1 quart bottle (Twin City Bottle), with vented caps, which was filled with the test solution and the lid screwed on.

The 1 quart bottles were stored in a closed cabinet at room temperature (about 20°C). All of the other formulas used 30 gm glass vials, which were filled with the test solution and the lids screwed on. The vials were stored on an open bench top under fluorescent light at room temperature (about The formulas with a at the end signifies that the test solution was stored at 50'C instead of The test solution, length of time tested and the test results are shown in Table 3. The synthetic hard water used was made by the method described in Official Methods of Analysis, Germicidal and Detergent Sanitizing Action of Disinfectants (Final Action) 960.09 page 139 "Synthetic Hard Water" (Section E).

The results are also shown in Figures 4-6.

Fig. 4 illustrates the concentration of performic acid in hard and deionized water over time. Fig. illustrates the concentration of hydrogen peroxide in hard and deionized water over time. Fig. 6 illustrates the stability of hydrogen peroxide and performic acid in deionized water over time.

While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one of ordinary skill in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.

TABLE 3 EF,g U/Pg 5o%H202 DIg TAPg HARDg DATE 7oH202 %PFA 599-56-1 10/7/93 0.44 1.2 20 10/7/93 2.09 0.009 599-56-3 10/8/93 0.44 1.2 20 10/8/93 2.11 0.0073 599-56-4 10/11/93 0.44 1.2 20 10/11/93 2.08 0.0065 599-56-5 10/11/93 0.44 1.2 20 10/11/93 2.08 0.015 599-56-6 10/12/93 0.44 1.2 20 10/12/93 1.91 0.0113 599-56-7 10/15/93 0.44 1.2 20 10/15/93 2.08 0.0154 599-57-11 10/8/93 0.88 1.2 20 10/8/93 2.11 0.0105 599-57-12 10/8/93 0.44 1.2 20 10/8/93 3.83 0.0089 599-64-13-H 10/25/93 0.44 1.2 20 500PPM Ca 10/26/93 2.3 0,0211 599-64-14-H 10/25/93 0.52 1.2 20 500PPM Ca 10/26/93 2.11 0.0130 599-65-15-T 10/26/93 0.44 1.2 20 10/26/93 2.06 0.0122 599-65-16-T 10/26/93 0.44 1.2 20 10/26/93 2.07 0.0105 599-65-17-T 10/26/93 0.88 2.4 20 10/26/93 2.86 0.0105 599-65-18-T 10/26/93 0.88 2.4 20 .10/26/93 3.9 0.0178 599-65-19-T 10/26/93 0.22 1.2 20 10/26/93 2.08 0.0049 599-65-20-T 10/26/93 0.22 1.2 20 10/27/93 2.06 0.0162

P"I

nx- "Wrr I T rT(N ;1JLpj Mi L _JEF~g JU/P,g 50%H202 IDI,g J TAP,g I HARD,g fDATE %H7.02 j%PFA 599-66-13 10/29/93 0.22 0.6 20 10/29/93 1.08 0.0057 599-66-14 10/29/93 0.22 0.6 20 10/29/93 1.07 0.0008 599-66-15 10/29/93 0.22 0.6 20 10/29/93 1.08 0.0081 599-66-16 10/29/93 0.22 0.6 20 10/29/93 1.09 0.0041 599-80-1 11/18/93 0.44 1.2 20 .11/19/93 2.06 0.0113 599-80-2 11/18/93 1'0.44 1.2 20 11/19/93 .2.08 0.0122 599-80-3 11/18/93 0.44 1.2 20 11/19/93 2.07 0.0105 599-80-4 11/18/93 0.44 1.2 20 11/19/93 2.08 0.0081 599-80-5 11/18/93 0.44 1.2 599-80-6 11/18/93 10.44 1.2 20 500PPM .11/19/93 2.02 0.0251 599-80-7 11/18/93 0.44 1.2 500PPM 11/19/93 2.09 0.0130 599-80-8 11/18/93 0.44 1.2 20 500PPM 11/19/93 2.07 0.0154 599-80-9 11/18/93 .0.44 1.2 20 1000PPM 11/19/93 2.07 0.0113 599-80-10 11/18/93 0.44 1.2 20 1000PPM 11/19/93 1.95 0,0113 599-81-11-Ca 11/19/93 0.44 1.2 20 SOOPPM CaC[1 11/22/93 2.05 0.0138 599-81-42-Ca 11/19/93 0.44 1.2 20 50OPPM CaC12 11/22/93 2.06 O00186 599-81-13-Bi 11/19/93 10.44 11.2 20 .22g/L BICARB 11/22/93 2.06 0.009 1EF~g U/P,g 50%H202 D DI,g JTAP,g J HARD,g [DATE J %H202 jF 599-81-14-Bi 11/19/93 0.44 1.2 .22g/L BICARB 11/22/93 2.02 0.0122 599-81-15-Bc 11/19/93 0.44 1.2 .22g/L BICARB 11/22/93 2.06 0.0178 599-81-16-Bc 11/19/93 0.44 1.2 .22g/L BICARB 11/22/93 2.05 0.0178 599-81-17 11/19/93 0.44 1.2 1 quart 11/22/93 2.11 0.0130 599-81-18 11/19/93 0.44 1.2 1 quart 11/22/93 2.14 1.2231 599-81-19 11/19/93 1.32 3.6 1 quart 111/22/93 5.28 0.0502 599-81-20 11/19/93 1.32 3.6 1 quart 11/22/93 5.26 0.0292 599-83-21 11/23/93 1.8 4.8 20 g 11/23/93 6.72 0.0340 599-83-22 11/23/93 _1.8 4.8 20 g 11/23/93 6.67 0.0292 599-83-23 11/23/93 1.8 4.8 50OPPM 11/23/93 5.88 0.0446 599-83-24 11/23/93 1.8 4.8 20 500PPM 11/23/93 6.75 0.0470 599-83-25 11/23/93 1.8 4.8 20 1000PPM 11/23/93 6.7 0.0446 599-83-26 11/23/93 1.8 4.8 1UO)OPPM 11/23/93 6.79 0.0494~ 599-83-27 11/23/93 1.8 4.8 20 I000PPM Ca 11/23/93 .6.72 0.0462 599-83-28 11/23/93 1.8 4.8 20 IOOOPPM Ca 11/23/93 6.73 0.0494 599-83-29 11/23/9.3 1.8 4.8 20 g 11/23/93 6.72 002 599-83-30 11/23/93 0 4.8 -20 g 11/23/93 6.9 008 "N j F,g t/P,g j50%H202 DI,g TAP-g HARD,g DATE %H202 j%PFA' 599-83-31 11/23/93 1.8 0 20 g 11/23/93 0.004 j 0.0032 534-28-1 2/15/94 0.4-4 1.2 20 g 2i15/94 mibdng time and temperature 534-29-1 2/15/94 0.44 18.76 2/17/94 2.12 0.0073 534-29-1T 2/15/94 0.44 0.8 18.76 2.12 0.0073 534-29-2 2/15/94 0.88 0.8 18.32 2/17/94 2.25 0.0275 534-29-2T 2/15/94 0.88 0.8 18.32 2/17/94 2.25 0.0275 534-29-3 2/15/94 0.44. 1.6 17.96 2/ 17/94 4.2 0.0219 534-29-3T 2/15/94 0.44 1.6 17.96 2/17/94 4.2 0.0219 534-29-4 2/15/94 0.88 1.6 17.52 4.32 0.0259 534-29-4T 2/15/94 0.88 1.6 17.52 2/17/94 4.32 0.0259 534-29-5 2/15/94- 1.76 1.6 16.64 4.5 0.0243 534-29-5T 2/15/94 1.76 1.6 16.64 2/17/94 4.5 0.0243 534-29-6 2/15/94 0.44 3.2 16,36 2/17/94 8.26 0.0284 534-29-6T 2/15/94 0.44 3.2 16.36 2/17/94 8.26 0.02,84 534-29-7 2/15/94 0.88 3.2 15.92 2/17/94 8.35 0.0251 534-29-7T 2/15/94 10.88 3.2 15.92 2/17/94 8.35 0.0251 534-29-8 2/15/94 1.76 15.04 8.64 0.0267 '.0 UFg jU/P,g 50%H202 [DI,g JTAP,g HARD,g jDATE J %H202 %PFA 534-29-8T 2/15/94 1.76 3.2 15.04 2/17/94 8.64 0.0267 534-29-9 .2/15/94 1.76 15.04 2/17/94 8.6 0.0535 534-29-9T 2/15/94 1.76 3,2 15.04 2/17/94 8.6 0.0535 534-29-10 2/15/94 3.52 13.28 2/17/94 9.63 0.0599 534-29-IOT 2/15/94. 3.52 3.2 13.28 2/17/94 9.63 0.0599 534-29-11 2/15/94 8 52 0 44.9 0.2349 534-29-11T 2/15/94 8 52 0 44.9 0.2349 534-29-12 2/15/94 6 54 0 46.8 0.5249 534-29-12T 2/15/94 6 54 0 46.8 0.5249 534-29-13 2/15/94 4 56 0 2/17/94 46.1 0.2584_ 534-29-13T 2/15/94 4 56 0 2/17/94 46.1' 0.2584 534-29-14 2/15/94 2 58 0 2/17/94 49.8 0.1393 534-29-14T 2/15/94 2 58 0 2/17/94 49.8 0.1393 534-29-15 2/15/94 10 50 0 2/17/94 45.6 0.4755 534-29-15T 2/15/94 10 50 0 2/17/94 45.6 0.4755 534-29-16 2/15/94 1.76 3.2 7.04 8g 1000PPM 2/17/94 8.48 0.0275 534-29-16T 2/15/94 1.76 7.04 1000PPM 2/17/94 8.48 0.0275 _IEF~g t/P,g [50%H202 jDI,g TAP,g J HARD,g ]DATE %H202, F 524-29-17 2/15/94 1.76 3.2 9.04 6g 1000PPM 2/17/94 8.61 0.0 43 524-29-17r' 2/15/94 1.76 3.2 9.04 IO00PPM 2/17/94 8.61 0.0543 524-29.18 2/15/94 1.76 3.2 11.04 4g 1000PPM 2/17/94 8.52 0.0697 524-29-18T 2/15/94 1.76 3.2 11.04 4g 1000PPM 2/17/94 8.52 0.0697 524-29-19 2/15/94 1.76 3.2 13.04 2g 1000PPM 2/17/94 8.58 0.068 524-29-19T 2/15/94 1.76 3.2 13.04 2g. IO00PPM 2/17/94 8.58 0.0680 529-29-20 2/15/94 1.76 3.2 14.04 Ig 1000PPM 2/17/94 8.57 .0.0680 529-29-20T 2/15/94 1.76 14.04 ig 1000PPM 2/17/94 8.57 0.0770 529-29-21 2/15/94 1.76 3.2 6.8 log 1000PPM 2/17/94 6.98 0.0770 529-29-21T 2/15/94 1.76 3.2 6.8 log 1000PPM 2/17/94 6.98 0.0648 529-29-22 2/15/94 0 16.8 2/17/94 8.14 0.064 529-29-22T 2/15/94 0 3.2 16.8 8.14 0.0356 529-29-23 2/15/94 0.44 0.8 18.72 .0 4 g COBRATEC 99 2/17/94 2.18 0.0356 529-29-23T 2/15/94 0.44 0.8 18.72 .04g COBRATEC 99 2/17/94 2.18 0.0186 529-9-2 2/5/9 0.4 1. 217/9 2.9 0018 529-29-24T 2/15/94 0.44 1.2 20 2/17/94 2.09 0.0154 529-29-25 2/15/94 0.44 11.2 1 20 2/17/94 2.09] 0,0170 I IT E~ /g5%22 D~ TAP,g HR,g DAE %H202 %/PFA 529-29-25T' 2/15/94 0.44 1.2 20 2/17/94 2.09 0.0170 529-29-26 2/15/94 0 3.2 16.8 2/17/94 8.66 004 529-29-26T! 2/15/94 0 3.2 16.8 2/17/94 8.66 0.4 N.3 DATE f %H202 I %PFA DATE %H202 J %PFA DATE %H202 J_%PFA 599-56-1 10/8/93 2.06 0.0154 10/11/93 2.07 0.0146 10/12/93 2.08 0.0162 599-56-3 10/11/93 2.09 0.0122 10/11/93 2.1 0.0122 10/12/93 2.1 0.0154 599-56-4 10/12/93 2.08 0.0138 10/14/93 2.07 0.0162 10/25/93 1.99 0.0041 599-56-5 10/12/93 2.07 0.0113 10/14/93 2.07 0.0138 10/15/93 2.06 0.0186 599-56-6 10/14/93 1.92 0.0130 10/25/93 1.86 0.0122 2/15/94 1.49 0.0105 599-56-7 10/25/93 2.04 0.0219 2/15/94 1.64 0.0146 599-57-11 10/8/93 2.15 0.0122 10/12/93 2.08 0.0162 10/14/93 2.04 0.0130 599-57-12 10/8/93 3.84 0.0073 10/12/93 3.78 0.0122 10/14/93 3.75 0.0105 599-64-13-H 10/26/93 2.09 0.0518 10/26/93 2.03 0.0154 10/26/93 2.04 0.0138 599-64-14-H 11/2/93 2.03 0.0186 11/18/93 1.84 0.0194 2/15/94 1.41 0.0535 599-6S-1S-T 10/27/93 2.03 0.0122 11/2/93 1.99 0.0049 11/18/93 1.85 0.0032 599-65-16-T 11/2/93 1.99 0.0049 11/18/93 1.85 0.0073 2/15/94 1.42 0.0186 599-65-17-T 10/27/93 3.81 0.0259 11/2/93 3.6 0.0113 11/18/93 3.13 0.0146 599-65-18-T 11/2/93 3.63 0.0170 11/18/93 31.5 0.0122 2/15/94 2.25 0.0105 599-65-19-T 10/26/93 2.06 0.0097 2/15/94 1.72 0.0211 599-65-20-T 2/15/94 1.67 0.0041 ROiI 'mi DATE ]%H202 %PFA JDATE %H202 J%PFA JDATE J%H202 %PFA 599-6.13 11/2/93 1.08 0.0081 2/15/94 0.93 0.0348 599-66-14 11/2/93 1.08 0.0081 2/15/94 0.94 0.0235 599-66-15 11/2/93 1.09 0.0041 2/15/94 0.96 0.0203 599-66-16 11/2/93 1.09 0.0057 2/15/94 0.94 0.0251 599-80-1 11/22/93 2.04 0.0073 2/15/94 1.59 0.0105 599-80-2 11/22/93 2.07 0.0162 2/15/94 1.65 0.0113 599-80-3 11/22/93 2.05 0.0097 2/15/94 1.64 0.0243 599-80-4 11/22/93 2.06 0.0154 2/15/94 1.61 0.0170 599-80-6 11/22/93 1.99 0.0146 2/15/94 1.56 0.0834 599-80-7 11/22/93 2.06 0.1539 2/15/94 1.56 599-80-8 11/22/93 2.04 0.0170 2/15/94 1.54 0.0656 599-80-9 11/22/93 1.03 0.0154 2/15/94 1.4 0.0810 599-80-10 11/22/93 1.94 0.0178 2/14/94 1.39 0.0640 599-81-11-Ca 2/14/94 1.6 0.0397 599-81-42-Ca 2/14/94 1.58 0.04131 599-81-13-Bi 2/14/94 1.64 0.0130 599-81-14-Bi 2/14/94 1.66 0.0130 Ifll ~I~T'Jj~A~'f ~1 I MW DTI, %H202 %PFA DATEI%H202 %PFADAE %27 599-81-15-Bc 2/14/94 106 0,0664 599-81-17 2/14/94 1.69 0.0105 599-81-18 2/14/93 1.5 0.0243 599-81-19 2/14/93 3.13 0.1134 2/15/94 3.15 0.0284 599-81-20 2/14/93 3.22 0.0486 2/15/94 3.2 0,0275 2/15/94 3.16 0.0308 599-83-21 12/3/93 5.58 1 0.0308 2/14/94 3.79 0.0365 599-83-22 12/3/93 5.38 0.0373 2/14/94 3.66 0.0340 599-83-23 12/3/93 4.97' 0.0624 2/14/94 3.26 0.0421 599-83-24 12/3/93 5.49 0.0632 2/14/94 3.69 0.0365 599-83-25 12/3/93 0.0923 2/14/94 3.39 0.0421 599-83-26 .12/3/93 5.41 0.0899 2/14/94 3.51 0.0713 599-83-27 12/3/93 5.63 0.0729 2/14/94 3.74 0.0421 599-83-28 12/14/93 3.74 0.0365 _599-83-29 1 12/14/93 3.76 0.0348 ;l I D ATE j%H202 I%PFA IDATE I %H202 ]%PFA JDATE J_%R202 %PFA 599-56-1 10/14/93 2.04 0.0138 10/15/93 2.02 0.0154 10/25/93 1.96 0.0073 599-56-3 10/14/93 2.08 0.0138 10/25/93 1.99 0.0081 10/27/93 1.98 0.0146 599-56-4 10/27/93 2 0.0073 2/15/94 1.52 0.0186 599 -56-5 10/25/93 1.98 0.0275 10/25/93 1.97 0.0267 10/27/93 1.98 0.0454 599-57-11 10/25/93 1.86 0.0130 2/15/94 0.95 0.0235 599-57-12 10/25/93 3.59 0.01 13 2/15/94 1.36 0.0194 599-64-13-H 10/27/93 2.04 0.0178 11/2/93 2 0.0178 11/18/93 1.82 0.0203 599-65-15-T 2/15/94 1.43 0.0065 599-65-17-T 2/15/94 2.24 0.0089

Claims

1. A method of sterilizing a medical device comprising contacting a surface to be sterilized of the medical device with an anti-microbial composition having improved anti- corrosive properties, wherein the anti-microbial composition is made by combining sufficient amount of an ester of formic acid, an oxidizer and water to provide about 0.01 to 10 wt.% of an ester of formic acid; from about 0.01 to 10 wt.% of an oxidizer; from about 0.001 to 5 wt.% of performic acid; and up to about 99.98 wt.% water.

2. A method according to claim 1, wherein the ester of formic acid is selected from the group consisting of ethyl formate, methyl formate, propyl formate, and mixtures thereof.

3. A method according to claim 1, wherein the oxidizer is 0 hydrogen peroxide. *0

4. A method according to claim 1, wherein the oxidizer is urea hydrogen peroxide.

5. A method according to claim 1, wherein the anti-microbial *0 composition further comprises an additive selected from the group consisting of corrosion inhibitors, stabilizers, and mixtures thereof.

6. A method according to claim 5, wherein the additive comprises: a) about 20% to 45% by weight mono sodium salt of phosphoric acid and mono (2-ethyl hexyl) ester of phosphoric acid; b) about 20% to 30 by weight pyrophosphonic acid, bis (2- ethyl hexyl) esters of pyrophosphonic acid, and sodium salts of pyrophosphonic acid; c) about 10 to 25% by weight polyphosphonic acids, 2-ethyl hexyl esters of polyphosphonic acids, and sodium salts of polyphosphonic acids; d) about 20% to 25% by weight water; e) less than 10% by weight phosphoric acid, bis (2-ethyl hexyl) esters of phosphoric acid, and sodium salts of phosphoric acid; f) less than 3% by weight 2-ethyl hexanol; and g) less than 5% by weight phosphoric acid, mono sodium salts of phosphoric acid and disodium salts of phosphoric acid.

7. A method according to claim 5, wherein the additive comprises 1,2,3-Benzotriazole.

8. A method according to claim 2, wherein the ester is ethyl formate. ee

9. A method according to claim 2, wherein the oxidizer is hydrogen peroxide. 2.5

10. A method according to claim 2, wherein the ester is ethyl formate and the oxidizer is hydrogen peroxide.

11. A method of reprocessing a catheter comprising contacting a surface of the catheter with an anti-microbial composition having improved anti-corrosive properties, wherein the anti- microbial composition is made by combining sufficient amount of an ester of formic acid, an oxidizer and water to provide about 0.01 to 10 wt.% of the ester of formic acid; from about 0.01 to 10 wt.% of an oxidizer; from about 0.001 to wt.% of performic acid; and up to about 99.98 wt.% water.

12. A method according to claim 11, wherein the ester of formic acid is selected from the group consisting of ethyl formate, methyl formate, propyl formate, and mixtures thereof.

13. A method according to claim 11, wherein the oxidizer is hydrogen peroxide.

14. A method according to claim 11, wherein the oxidizer is urea hydrogen peroxide.

A method according to claim 11, wherein the anti- microbial composition further comprises an additive selected from the group consisting of corrosion inhibitors, stabilizers, and mixtures thereof.

16. A method according to claim 15, wherein the additive 20 comprises: a) about 20% to 45% by weight mono sodium salt of phosphoric r acid and mono (2-ethyl hexyl) ester of phosphoric acid; b) about 20% to 30 by weight pyrophosphonic acid, bis (2- ethyl hexyl) esters of pyrophosphonic acid, and sodium 22 salts of pyrophosphonic acid; c) about 10 %.to 25% by weight polyphosphonic acids, 2-ethyl hexyl esters of polyphosphonic acids, and sodium salts of h. polyphosphonic acids; d) about 20% to 25% by weight water; e) less than 10% by weight phosphoric acid, bis (2-ethyl hexyl) esters of phosphoric acid, and sodium salts of phosphoric acid; f) less than 3% by weight 2-ethyl hexanol; and g) less than 5% by weight phosphoric acid, mono sodium salts of phosphoric acid and disodium salts of phosphoric acid.

17. A method according to claim 15, wherein the additive Somprises 1,2,3-Benzotriazole.

18. A method according to claim 12, wherein the ester is ethyl formate.

19. A method according to claim 12, wherein the oxidizer is hydrogen peroxide.

A method according to claim 12, wherein the ester is ethyl formate and the oxidizer is hydrogen peroxide.

21. A method of reprocessing a catheter comprising contacting a surface of the catheter with an anti-microbial composition having improved anti-corrosive properties, wherein the anti- f 0 microbial composition is made by combining sufficient amount of an ester of formic acid selected from the group 0 consisting of ethyl formate, methyl formate, propyl formate, and mixtures thereof, an oxidizer and water to provide about 0.01 to 10 wt.% of an ester of formic acid; from about 0.01 to 10 wt.% of the oxidizer; from about 0.001 to 5 wt.% of performic acid; and up to about o 99.98 wt.% water. 0 o.

22. A method according to claim 21, wherein the oxidizer is hydrogen peroxide.

23. A method according to claim 21, wherein the oxidizer is urea hydrogen peroxide.

24. A method according to claim 21, wherein the anti- microbial composition further comprises an additive selected from the group consisting of corrosion inhibitors, stabilizers, and mixtures thereof. mm

25. A method according to claim 24, wherein the additive comprises: a) about 20% to 45% by weight mono sodium salt of phosphoric acid and mono (2-ethyl hexyl) ester of phosphoric acid; b) about 20% to 30 by weight pyrophosphonic acid, bis (2- ethyl hexyl) esters of pyrophosphonic acid, and sodium salts of pyrophosphonic acid; c) about 10 to 25% by weight polyphosphonic acids, 2-ethyl hexyl esters of polyphosphonic acids, and sodium salts of polyphosphonic acids; d) about 20% to 25% by weight water; e) less than 10% by weight phosphoric acid, bis (2-ethyl hexyl) esters of phosphoric acid, and sodium salts of phosphoric acid; f) less than 3% by weight 2-ethyl hexanol; and g) less than 5% by weight phosphoric acid, mono sodium salts of phosphoric acid and disodium salts of phosphoric acid.

26. A method according to claim 24, wherein the additive comprises 1,2,3-Benzotriazole.

27. A method according to claim 21, wherein the ester is ethyl formate. e0 *0 q

28. A method according to claim 21, wherein the ester is St 3 0 ethyl formate and the oxidizer is hydrogen peroxide.

29. A method of sterilising a medical device in accordance with example 1, 2 or.3.